A ventilator is configured to assist a user with breathing, while eliminating the need for extraneous sensors and tubing normally found in prior art ventilators. The ventilator relies on a predetermined relationship between a measurable quantity associated with a compressed gas and the maximum pressure of that compressed gas upon delivery to the user. The measurable quantity may be mass flow rate of the compressed gas or pressure within a delivery lumen used to transport the compressed gas, among others. Based on the predetermined relationship, the control logic within the ventilator determines whether the pressure of compressed gas delivered to the user exceeds a maximum allowable pressure. When the maximum pressure is exceeded, the control logic initiates corrective action to reduce the pressure of the compressed gas.
